libxl: fix memory leak in libxl_cpuid_dispose

libxl_cpuid_policy_list is not allocated with GC-aware allocation so it
needs to be freed manually, just like what libxl_string_list_dispose and
libxl_key_value_list_dispose do.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

tools/libxl/libxl_cpuid.c

@@ -26,6 +26,7 @@ void libxl_cpuid_dispose(libxl_cpuid_policy_list *p_cpuid_list)
             if (cpuid_list[i].policy[j] != NULL)
                 free(cpuid_list[i].policy[j]);
     }
+    free(cpuid_list);
     return;
 }